You could probably have Matt back on his body using the "Futurama theorem".Wish solved an issue like this on a Futurama episodehttps://theinfosphere.org/Futurama_theoremYou could have Britney and mr Ambrose as spares, but leave mr Ambrose on Mrs Ambrose body at he end
Matt in Mrs Ambrose swaps with Britney.Matt in Britney swaps with fake Mrs Ambrose in Matt.Britney in Mrs Ambrose swaps with Mr Ambrose.Britney in Mr Ambrose swaps with fake Mrs Ambrose on BritneyMatt and Britney are back on their bodies, fake Mrs Ambrose gets to be male...Mr Ambrose... He had it coming
I mean, you could have Mr Ambrose and "Mrs Ambrose" where they started before everything, but like this is poetic Justice
I doubt after that one night Mark will go through with his plan to switch. plans have a way of changing
Or he might not end up wanting to be his sister after all.